This invention relates generally to medical devices and methods of using the same, and more particularly, to an endovascular stent graft and methods for placement and deployment of the graft in the lumen of a branched vessel.
Stent grafts may be inserted into an anatomical vessel or duct for various purposes. For example, stent grafts are used for treatment of vasculature in the human or animal body to bypass a repair or defect in the vasculature or to maintain or restore patency in a formerly blocked or constricted passageway, such as following a balloon angioplasty procedure. For example, a stent graft may extend proximally and/or distally away from a vascular defect, including a diseased portion of an aneurysm, and engage a healthy portion of a vessel wall. In many cases, however, such a damaged or defective portion of the vasculature may include a branch or side vessel such as an internal iliac artery extending from the common iliac artery. Thus, it has been proposed to provide a stent graft having a side branch which, when deployed, is positioned over the opening to the internal iliac artery and then, if desired, another stent graft can be deployed through the side branch into the internal iliac artery to bypass a diseased portion thereof and restore the blood flow path to the internal iliac artery.
Generally, when deploying an endovascular stent graft into a vessel lumen, it is possible to obtain access to such a lumen from one or both ends of the vessel where necessary, thereby facilitating placement of a graft in the desired portion of the lumen. However, the internal iliac artery, which extends from the common iliac artery below the aortic bifurcation, is a blind vessel because there is no practical way of performing a minimally invasive endovascular procedure into that vessel other than by entry from the common iliac artery.
Access to and introduction of a stent graft into the common and/or internal iliac arteries and successful deployment of a stent graft in such vessels may often depend upon a favorable layout of the arteries and, in many cases, access is difficult. One known approach that has been used includes accessing the target location(s) within the vessels by a contralateral or crossover approach. In other words, a guide wire and/or sheath may be first introduced into a common iliac artery and then snared or pulled from the contralateral side so that the wire and/or sheath extends across the aortic bifurcation where it can be positioned proximal to the opening of the internal iliac artery in which treatment or repair is desired. In this way, a pathway is created to facilitate the introduction and deployment of a stent graft to the target location in the contralateral internal iliac artery.
As endovascular techniques become more refined, physicians continue to seek novel alternative approaches to treating diseased vessels, including blind vessels that are difficult to access and traverse. For example, accessing the target location(s) within the internal iliac artery using an ipsilateral approach (as opposed to the contralateral approach) and therefore avoiding the above-described “crossover” manipulation of a guide wire or sheath over the aortic bifurcation is desirable. Accordingly, a method for accessing the internal iliac arteries utilizing an ipsilateral approach and a pre-loaded deployment system to enable such a method to be practiced is described herein.
While this invention will be generally discussed in relation to a stent graft and method of deployment thereof into a common iliac artery where it is necessary to extend a side branch from a main portion or body of the graft into an internal iliac artery, it is also contemplated that the invention is not so limited and may relate to any body or vessel lumen in which such a deployment is necessary or desired.